Computational fluid dynamics of steam flow in a turbine control valve with a bell-shaped spindle

Wang, Peng; Ma, Hongyu; Quay, Bryan D.; Santavicca, Domenic A.

doi:10.1016/j.applthermaleng.2017.10.104

Cited by 22 publications

(4 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lu et al [17] and Agrež et al [18] also analyzed steam throttling in steam turbine valves and concluded the amount of entropy generated during thermodynamic transformation is closely related to the degree of steam throttling. Wang et al [19], Mambro et al [20], and Guo et al [21] analyzed the steam turbine at minimum flows, where they also found increased entropy generation and a consequently decreased cycle efficiency. As already mentioned, the expansion curves for various modes of steam turbine opera-tion constructed using the real process data confirm exactly this.…”

Section: Discussionmentioning

confidence: 99%

Off-design flow analysis of cogeneration steam turbine with real process data

2022

View full text Add to dashboard Cite

This paper presents the concept of reconstruction of the existing coal-fired combined heat and power plant to comply with new European environmental policies. The existing coal-fired boiler will be replaced by two new dual pressure heat recovery steam generators, which will utilize the exhaust gas heat from two new gas turbines. The steam from the heat recovery steam generators will be fed to the existing steam turbine. After the reconstruction, the nominal turbine inlet steam mass-flow of 40 kg/s will be reduced to 30 kg/s. During periods of low heat demand, only one gas turbine and one heat recovery steam generator will be in operation and the live steam mass-flow may drop even to 12 kg/s. Prior to the reconstruction, dedicated tests of the existing steam turbine were carried out using the steam from the existing coal-fired boiler. The goal of the test was to verify the viability of operation with such an extremely low mass-flow. The results of tests show that such operation is possible but inefficient from a power generation point of view. Besides this, the turbine control algorithm needs to be accommodated to this extreme operating regime and additional measures like displacement of the extraction points and steam cooling will be required to control the temperature of the steam extractions. The novelty of this paper is using real pre-reconstruction process data for the assessment of feasibility and efficiency of the post-reconstruction operation of a combined heat and power turbine.

show abstract

Section: Discussionmentioning

confidence: 99%

Off-design flow analysis of cogeneration steam turbine with real process data

2022

View full text Add to dashboard Cite

show abstract

“…Shiyang et al [13] studied the dynamic characteristics of a solenoid valve using transient CFD numerical calculations and experiments. Some authors [14,15] used the Reynolds-Averaged Navier-Stokes (RANS) simulation method with the shear stress transport (SST) turbulent closure to analyze flow properties in turbine control valves. In general, these works focused more on the flow properties in valves; they do not address the issues of the combined heat transfer characteristics in fluids and high-pressure pneumatic control valves.…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Investigation of the Conjugate Heat Transfer for a High-Pressure Pneumatic Control Valve Assembly

Ngwa

Gao

2022

Entropy

View full text Add to dashboard Cite

This paper uses heat transfer experiments and computational fluid dynamics (CFD) simulations to investigate the conjugate heat transfer (CHT) in a high-pressure pneumatic control valve assembly. A heat transfer test rig was constructed, and time–temperature histories of five test points placed on the valve assembly’s outer surface were recorded for study validation. The Unsteady Reynolds-Averaged Navier–Stokes (URANS) CFD methods with the standard k-ɛ turbulence closure equations were adopted in the numerical computations. Polyhedral grids were used; time step and mesh convergence studies were conducted. Simulated and measured temperatures profile comparisons revealed a good agreement. The CHT results obtained from CFD showed huge velocity fields downstream of the valve throat and the vent hole. The airflow through the valve was icy, mainly in the supersonic flow areas. Low temperatures below 273.15 K were recorded on the internal and external walls of the valve assembly. The consistency of the measured data with the numerical results demonstrates the effectiveness of polyhedral grids in exploring the CHT using CFD methods. The local entropy production rate analysis revealed that irreversibility is mainly due to viscous dissipation. The current CHT investigation provides a potential basis for thermostress analysis and optimization.

show abstract

“…The steam turbine uses high-pressure steam produced by the boiler to rotate its main shaft, and the main shaft drives the generator through a hydraulic coupling to generate electricity by excitation. As the most widely used prime mover equipment in the power industry [1], the steam turbine is widely used in the metallurgical industry, chemical industry, and ship power systems [2,3]. The electrohydraulic regulating system for the steam control valve, usually called the servomotor (referred to as SM), plays a very important role in the steam turbine.…”

Section: Introductionmentioning

confidence: 99%

Position Control Study on Pump-Controlled Servomotor for Steam Control Valve

Yan

Jin

Zhang³

et al. 2021

Processes

View full text Add to dashboard Cite

In steam turbine control and actuation, the steam control valve plays a key role in operability and reliability. The electrohydraulic regulating system for the steam control valve, usually called the servomotor, needs to be reliable and high performing under nonlinear excitation interference in actual conditions. Currently, electrohydraulic servo valve control technology is widely used in servomotors. Although this technology has good control performance, it still has some technical defects, such as poor antipollution ability, low energy efficiency, large volume size, and limited installation space. Aiming at the abovementioned technical shortcomings of electrohydraulic servo valve control technology, a servomotor-pump-hydraulic cylinder volume control scheme is proposed in this paper, forming a pump-controlled servomotor for the steam control valve. By analyzing the working principle of the pump-controlled servomotor position control in the steam control valve, the mathematical model of a pump-controlled servomotor for the steam control valve is established. The sliding mode variable structure control strategy is proposed, and the variable structure control law is solved by constructing a switching function. To verify the performance of the proposed control method, experimental research was conducted. The research results show that the proposed sliding mode variable structure control strategy has a good control effect, which lays the theoretical and technical foundation for the engineering application and promotion of pump-controlled servomotors for steam control valves and helps the technical upgrade and product optimization of steam turbines.

show abstract

Computational fluid dynamics of steam flow in a turbine control valve with a bell-shaped spindle

Cited by 22 publications

References 21 publications

Off-design flow analysis of cogeneration steam turbine with real process data

Off-design flow analysis of cogeneration steam turbine with real process data

Numerical and Experimental Investigation of the Conjugate Heat Transfer for a High-Pressure Pneumatic Control Valve Assembly

Position Control Study on Pump-Controlled Servomotor for Steam Control Valve

Contact Info

Product

Resources

About